Abstract: This invention relates to an antenna comprising at least one radiating device, furnished with a rejector filter associated with a frequency band of an interfering signal. In accordance with the invention, such an antenna is characterized in that this rejector filter is adaptive, so as to be active when the interfering signal is detected and its power is above a threshold, this adaptive filter being deactivated when the detected power of this interfering signal is below the threshold.

Abstract: The invention relates to a data transmission system comprising an antenna provided with a monopole radiating element held in place by an earth plane provided with a conducting surface. According to the invention, the radiating element is located facing the surface of the earth plane so as to interact with the latter in order to improve its performance.

Abstract: The invention is a device and a method for cancelling interferences between signals with frequency proximity, inherent to the co-location of multi-standard terminals, in a communication system.

Abstract: The method of improving the carrier-to-noise ratio for a receiver with diversity, and the associated device, consists, after extracting, by phase shifting, the noise component of the signals to be demodulated, in optimizing the cancellation of the useful component via a feedback loop acting on the phase shifter and in summing the noise component in phase and in phase opposition with these signals to improve the carrier-to-noise ratio.

Abstract: The present invention relates to a broadband monopole antenna comprising a “cup”-shaped radiating element mounted on an earth plane forming support of annular shape. This antenna can be used in the field of portable television apparatuses.

Abstract: The invention relates to a wideband phase shift device. A phase shift ? is introduced on the fixed frequency local oscillator. The principle of the invention is to realise a double translation of the input signals. The phase variation introduced at the level of the local oscillator has a positive value on one of the translated signals and a negative value on the other. The signals are recombined at the reception frequency with a phase difference of 2 ? so as to maximise the amplitude of the signal at the output of the summator.

Abstract: The reception device according to the invention enables, through a predictive detection of fading on the channels adjacent to the selected channel n, the phase of the incoming signals received from secondary antennas to be corrected so as to eliminate the fading.

Abstract: The present invention relates to a radiating element designed to operate in an electrically small antenna including a conducting strip folded N times like a bellows.

Abstract: The antenna, particularly for portable televisions, comprises two ports coupled to a radiating element (11), the two ports being placed on the radiating element at 90° to each other and at 45° relative to a horizontal plane. The two ports are linked to a broadband switching and phase shifting circuit controlled in order to supply a polarization diversity signal as output.

Abstract: The invention proposes a filtering device having a frequency response which is symmetrical, using asymmetrical filters coupled by transposition means. The advantageous characteristics of the asymmetrical filters are retained and the faults associated with the asymmetry are eliminated. The asymmetrical filters are, for example, quartz filters. The invention also proposes an external transmission and reception unit, using the filtering device with the application of the filtering method.

Abstract: The present invention concerns a system of receiving signals comprising a retransmission base to amplify signals captured at a point in a domestic environment and retransmit them at the same frequency to digital receivers of the said domestic environment. According to the invention, the retransmission base amplifies and retransmits up to N DVB-T channels the positions of which can be anywhere in the receive band and are chosen dynamically by the system users. Means are provided in the system to share the system's amplification resources between the system's various digital receivers.

Abstract: The invention relates to a device for converting frequencies comprising a local oscillator of fixed frequency and a first mixer with two inputs and an output, a first input receiving the signal to be converted and a second input receiving the signal arising from the local oscillator. It further comprises a second mixer with two inputs and an output, a first input receiving the signal arising from the phase-shifted local oscillator and the second input receiving a dc signal whose value is dependent on the power of the residual spectral component at the output of an adder receiving as input the signals arising from the first and from the second mixer(s) and giving as output a transposed signal. The invention applies in particular in terminals operating in the Ka band.

Abstract: The invention relates to VHF adapters for cable networks of the ODU type. It consists in using two conversion chains, up and down, in which a very stable signal reference oscillator drives means of generating the VHF and IF local frequencies common to these two conversion chains. A very selective surface wave filter makes it possible to rject the frequency of the local oscillator at the level of the first intermediate frequency. It makes it possible to obtain a DOCSIS compatible millimeter MWS ODU whose frequency stability and spectral purity satisfy the constraints of the cable standard without undertaking spectral inversion of the signals transmitted and received.

Abstract: The antenna, particularly for portable televisions, comprises two ports coupled to a radiating element (11), the two ports being placed on the radiating element at 90° to each other and at 45° relative to a horizontal plane. The two ports are linked to a broadband switching and phase shifting circuit controlled in order to supply a polarization diversity signal as output.

Abstract: The invention relates to a transmission or transmission/reception device having a transmission path structure which makes it possible to increase the range of variation of the transmission power without degrading the signal-to-noise ratio. The attenuation is achieved in part in an internal unit 5 and in part in an external unit 4 with the aid of a switching circuit 25 which selectably couples an antenna between an output or an input of an amplifier.

Abstract: The invention provides a dielectric resonator oscillator DR, especially for transmission devices whose oscillating frequency may take several values. The oscillator uses two interfering conductors 30 and 31 switched so that they may or may not form a metal plane close to the dielectric resonator DR in order to vary the frequency of the oscillator while using a single resonator. The interfering conductors 30 and 31 are located in the cavity CAV close to the resonator DR and the switching means may or may not establish an electrical contact between the said interfering conductors 30 and 31.

Abstract: The invention relates to processes and devices which make it possible to directly modulate an RF carrier with a quadrature signal. It consists in filtering (504) this quadrature signal around zero so as to introduce alternately (507, 508) on each of the channels a low-frequency subcarrier that will serve as reference. Each of these channels is alternately demodulated in a synchronous manner (519) cosine-wise and sine-wise. The demodulation signal is filtered (523) so as to recover the subcarrier marred by modulation errors. The measurement of these errors (524) allows feedback correction (503) of the quadrature signal. It makes it possible to perform the major part of the operations in the digital processor (501) and enables direct vector modulation to be made possible at millimetre frequencies.

Abstract: The invention relates to a dielectric resonator oscillator, comprising a dielectric resonator contained in a resonant cavity in order to generate a signal oscillating at a predetermined central frequency, the dimensions of the resonator and the limiting conditions in the cavity being capable of determining the resonant frequency of the resonator. It comprises means sensitive to acoustic pressure waves capable of modifying the distribution of the electromagnetic fields in the cavity as a function of said acoustic pressure waves. The invention also relates to a voice control device equipped with an oscillator according to the invention. Particular application to remote voice control devices for controlling domestic equipment.

Abstract: In this process for producing ethanol by enzymatic treatment of a must of a starchy plant material with yeasts of the genus Saccharomyces, all the old yeasts are replaced with fresh yeasts in order to keep the fermentation time between 20 and 24 hours.

Abstract: The invention relates to a dielectric resonator oscillator, comprising a dielectric resonator (4) contained in a resonant cavity (2) in order to generate a signal oscillating at a predetermined central frequency, the dimensions of the resonator and the limiting conditions in the cavity being capable of determining the resonant frequency of the resonator.